What happens when pregnant mares eat chasteberry?

Hello, can anyone tell me what happens when pregnant mares eat chasteberry? I've been searching the internet for a while, but I just can't find an answer…

I know that chasteberry has a positive effect on a horse's fertility, but what happens is if you give chasteberry to a pregnant mare because you haven't weaned her after insemination, for example.

*I don't have a pregnant mare and am just asking this out of curiosity. I would be very grateful for an answer.

Best regards!